Sentence Structure: Compound and Complex

Contributor: Kristen Gardiner. Lesson ID: 10498

Because it's important. Makes you smart. What are we talking about? If these were complete sentences, you'd know I was talking about studying compound and complex sentences! Learn about them today!



English / Language Arts
learning style
personality style
Golden Retriever
Grade Level
Intermediate (3-5)
Lesson Type
Quick Query

Lesson Plan - Get It!


comic on clauses

Compound and complex sentences means combining clauses and phrases to make more interesting sentences.

All sentences include a subject and a predicate:

  • The subject of the sentence usually tells what the sentence is about.
  • The predicate of a sentence tells about the subject or tells what the subject is doing.

A sentence begins by capitalizing the first letter of the first word, and it can end with a period, question mark, or exclamation point. The end punctuation depends on whether the sentence is interrogative, exclamatory, declarative, or imperative. (For a review of interrogative, exclamatory, declarative, and imperative sentences, refer to the Elephango lessons found in the right-hand sidebar under Additional Resources.)

Sentences should always convey a complete thought, for example, "Kevin ate lunch." This particular sentence is not very long, but it has a subject (Kevin) and a predicate (ate lunch). This sentence also conveys a complete thought.

Now that you have reviewed simple sentence structure, take a look at how clauses and phrases help you make more interesting sentences.


A phrase is a part of a sentence that does not contain its own subject and predicate.

For example:

  • "after school" (this phrase tells when, but it is neither a subject nor a predicate)
  • "at the video game store" (this phrase tells where, but it is neither a subject nor a predicate)
  • "with the long brown hair and blue sweater" (this phrase tells which, but is neither a subject nor a predicate)

You might recognize these as prepositional phrases if you have learned about prepositions. If you need a refresher on prepositions, download the Preposition Review from the Downloadable Resources in the right-hand sidebar, or take a quick look at the Elephango lesson under Additional Resources before moving on to the Got It? section.


A clause is a group of words that includes a subject and a predicate. Remember:

Subject The noun, noun phrase, or pronoun in a sentence or clause that tells who does the action or what is described by the predicate.

Predicate The part of a sentence that tells what the subject does or that describes the subject, including the verbs, objects, and phrases directed by the verbs.

Example: "Carol stood outside the gate."

Types of clauses


  • An independent clause is a clause that can STAND ALONE as a sentence.
  • It does NOT need to be attached to another clause.
  • It is a complete thought.


  • The boy played baseball all day.
  • The cat chased the mouse around the house.
  • I went to karate practice after school.

An independent clause is a complete, simple sentence. It has a subject and predicate and can do just fine by itself.

Dependent or subordinate

  • not a stand-alone sentence
  • A dependent clause is a clause that does not complete a thought, and must be accompanied by an independent clause.
  • A dependent clause usually begins with a conjunction (If you need a review of conjunctions, you can take a look at the Elephango lesson under Additional Resources.)


  • Carol stood outside the gate because it was locked.

In this example, the phrase "because it was locked," wouldn't make any sense if it were standing by itself, but when attached to the independent clause, it helps to explain the reason why Carol was outside the gate.

Putting it all together

There are four types of sentence structures you can use to vary your writing. Many of us already use different sentence structures in our everyday writing without even knowing it. What you are learning in this lesson is how to recognize the different sentence structures and make sure you are using proper punctuation, conjunctions, and prepositions in your writing. And, most importantly, how to make your writing more interesting!

Simple sentences

  • simple sentence = verb clause
  • subject | predicate
  • "The dancer | sat on the pie."

Compound sentences

  • compound sentence = independent clause + independent clause
  • correlating conjunction | independent clause | coordinating conjunction | independent clause
    "Either | you need to study harder | or | you need to drop the class."
  • independent clause | coordinating conjunction | independent clause
    "Carol stood outside the gate,| and | Rick came to unlock it."

NOTE: Use a comma when you join the sentences with a coordinating conjunction ("for," "and," "nor," "but," "or," "yet," "so"), or use a semicolon (;) if you use no connecting word.

Complex sentences

  • complex sentence = independent clause + dependent clause
  • complex sentence = independent clause + phrase
  • dependent clause | independent clause
    "Because it rained, | the museum cancelled the picnic."
  • independent clause | prepositional phrase
    "I will join you for lunch | after I wash my hands."
  • prepositional phrase | independent clause | prepositional phrase
    "After she left work, | the woman stopped at the store | before she went home."

NOTE: If you begin a sentence with a subordinating conjunction (such as "because") or a prepositional phrase, set the phrase or clause apart from the independent clause with a comma.

Compound-complex sentences

  • compound-complex sentence = independent clause + independent clause + dependent clause
  • compound-complex sentence = independent clause + independent clause + phrase
  • independent clause| dependent clause |coordinating conjunction | independent clause
    "Glen went to the store | because he needed more milk, | and | then he made pudding."
  • dependent clause | independent clause | coordinating conjunction |independent clause
    "Since Maggie came home, | she's been very moody, | so | please be nice to her."
  • independent clause | prepositional phrase| conjunction | independent clause |prepositional phrase
    "Earl went on vacation | after the holiday, | but | he said the place became very crowded | after he was there only a few days."

NOTE: Same punctuation rules as above apply!

Now that you've got all of that straight, continue on to the Got It? section for some practice!

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